Fire control computer



pri 30, 1935. s, MYERS Er AL 1,999,358

' FIRE CONTROL COMPUTER' Filed Jan. 23, 1932 5 Sheets-Sheet 3 fg, f f fwgg 'rr-irse stares j resets-e rarest orifice.

FIRE CONTROL COMPUTER Shiereld G. Myers, Freeport, and Earl `W. Chafee, Brooklyn, N. Y., assignors to Sperry Gyroscope Company, lino., Brooklyn, N. Y., a corporation of New York Application January 23,

7 Claims.

, 'This invention relates to range and bearing computers for assisting in the aiming of long range ordnance. Manyvery complicated and expensive computing devices have been proposed, known generally as range and bearing keepers which attempt to generate the range and bearing continuously from angles put into the instrument directly from the sighting telescope and range finders. By our invention We obtain equally as good or better results with a greatly simplied mechanism by devising an instrument into Which it set range and bearing data M'Referring wto Vthe"drawings showing several forms of the invention,

Fig. l shows in schematic form the azimuth part of our instrument.

Fig. 1-.-A detail of the variable speed drive.

Fig. 2 shoivsin similar form the range and elevation portion of our instrument.

Fig. 3 is a detail-of one of the setting mechanisms employed in Fig. 2.

Fig. 4 is a plan view of a portion of the zoneV of fire indicating disc.

Fig. 5 is a transverse section of the same.

Fig. 6 is a diagram illustrating the mathematical principles involved in a portion of Fig. 2.

Fig. 7 is a plan view of certain representative indicating dials.

Fig. 8 is a sectional View of the same.

Fig. 9 is a detail of the percent range cam employed in Fig. 2.

Fig. 10 is a detail of the cam employed to shift the range-elevation cam pin from cam to cam.

TEELRU..Qillllillllllihnun n.Eigv 1 iS.,tgmestablishnofiowhoi uncorrected azimuth (future or prefiere@i arenile@afina i551 agreement -v{vith that read atwrvegular time intervissierii 'M *iffruiimg bo`a`'d'a" tl to A trai'isznrt this azimuth pluth'el'crrecti'n-in azimuth as coiected'ziintlj Br future target bearings tothe bearingnd'i'c'ator at the guns. For this purpose there is provided a clockregulated constant speed motor i that continuously rotates a disc 2 through suitable gearing HU and l H. On said disc bears a variable speed ball 3 which bears at its other side on a cylinder 4. It will readily be seen that as the ball 3 is moved toward and away from the-center of rotation of the disc 2 that the speed of rotation transmitted to the cylinder 4 will vary from a maximum in one directionthrough zero to a maximum in the other direction. The setting of the 1932, Serial No. 588,472

(cil zes-615) ball is controlled from a handwheel 5 on a shaft 6 which drives through gearing 8l, stub shaft 82, Worm gears 83 and shaft 813, said shaft having a pinion 87 thereon. Said pinion meshes with rack teeth 88 on a sliding carriage 39 which carries the ball 3 so as to adjust the ball laterally atl will (see Fig. l-A) Turning of the handwheel 5 also positions the dial 5l on shaft 34, the dial being setI to show. at this stage the estimated rate of change of azimuth cr bearing.

The resulting rotation of the cylinder l rotates through suitable gearing l i'l--i iB-and cross shaft l Id the Worm shaft 7 and Worm and wormy r mounted on the main shaft i3 but clutch inember lli is splined thereto so that vby throwing the clutch member into engagement with the clutch face oi one or the other of the Wormivheels, shaft i3 may be driven at two different speeds from the cylinder d. This or an equivalent arrangement is for the purpose of increasing the effective range of variation vof speed Without unduly lengthening the roller li.

The output of shaft i3 is led into a diierential gear train l5, the planetary arm of Which isrotated from the Worm I5 and shait 1S of the handwheel il. The other arm of the gear train is connected to the output shaft i3. Ehe function of the handivheel i? is to introduce the bearins @riesgos-.S @fiile rates iffieii f's the indicati ns s the machine is ino'pe'ation'and Without interfering with theoriginal settings. For this purpose the movements of the handwheel li are also carried back to the shaft G through gears 85 and shaft S6, but since a change speed gear is employed in the primary transmission lWe prefer to also employ a change speed clutch arrangement 20 between the shafts i6 and B. As shown, there is splined on the shaft 2i a clutch member 20 which may be brought into engagement with oneor the other of the clutch faces 22-23, secured respectively to gears 24 and 25. Said gears-are of different diameter and are connected together through complementary gears 2".'-28 on shaft E8. It will readily be seen, therefore, that by moving the clutch member 2li in engagement with one or the other or" clutch faces 22-23 that the shaft 30 may bedriven at two different speeds. Preferably the controlling arms 3l and 32 of the two clutch members are tied together as by rod 33 so that the throwing of one clutch by handle 89 automatically throws the other clutch. Shaft 2l is coupled to the shaft 6 rat shows the pred t w"In 'operation seconds at the ring of a bell in accordance with eleiilnaboald lea.

change.

the bearing read from the plotting board so that continuous bearing changes are being fed into the instrument. This uncorrected bearing is trans mitted through the shaft i3, gears Si) and Worm and Worrmvheels SLL-35i' to the coarse and iine dials 35-35'. To assist the operator there may be superimposed on the dials 35 and 35 setting knobs 48, 139 pivoted on the glass cover and each connected to an auxiliary pointer 5B, 5G" (see Fig. Y). llieau laryzeointers marleasiiiateensif @signataires P and P on the dials 35' do not match the set pointers at the time the bell rings, the hand-wheel l'l vis quickly turned to bring the two pointers and indices into coincidence. This operation not only changes the transmitted bearing but at the same time applies a correction to the rate through the shafts 2l and 35 as explained. Whenjfiilsvt starting the instrumenthhotylenver,anothehardle 3 is set forwthe estimated uncorrectedfuture azimuth AP as read from the plotting board thus turning the shaft i8. This is selected by the plotter as the point P on the board where the shell Will strike the target, points pi, p2 and n3 being plotted points of present position (Fig. 6)

The outpecisljjrjtfwhich, therefore, represents correctedmbearings is led through gearing Si, Si' to another differential 3l, the opposite arm of which is set from a handle 3S in accordance with the indicated corrections in azimuth, such as the ballistic and spotting corrections. These corrections are set up on the coarse and ne dials 39, 39 and are fed into differential 3T through the gears l, shaft liii and gears E2. The output ofthe differential is connected to the shaft i3 which turns through gearing 92, worin shaft 93 having thereon Worms 1M, 411', and shafts 45 and 35 to which are connected the coarse and fine target bearing or azimuth transmitters 4B, 6"' and also the corrected azimuth indicating dials al, 4l.

In operating this portion of our invention the two clutches i4 and 2G are rst left open and the variable speed motor started. The approximate rate of change of bearing is then set up on the dial 5l through the handwheel 5, thus setting the position of the roller on the. cylinder, Next, the handwheel 3S is turned to set in the uncorrected azimuth on dials 35, 35' as indicated as the true estimated bearings on the plotting board. The selector clutch lil is then thrown in to either fast or slow speeds thus throwing in the clutch 2i] at the same time. The flow of azimuth data to the guns is now started, the data being based on the azimuth setting and the approximate rate of The instrument is operated in connecl tion with a bell which rings periodically, say every 30 seconds, and before the second bell rings after the instrument starts the operator should ob- !s'erve Whether the dials 55 and 35' indicate the .correct azimuth. If not, handle Il is turned tuntil the pointer 5D on the dials match the ining transmitted through the transmitters 115, d6 and also shown on dials 37, 4l.

The range or elevation computing portion of the instrument is shown diagramznatically in Fig. 2. The initial settings are quite similar to the azimuth settings. Thus there is again provided a constant speed motor l for driving a variable speed shaft 'i' of roller il', the variable speed roller S being set from the handle 5' as before through gearing 95, H5, H5, shaft 84', gearing li'l and pinion 8l. gaid handle isrotatedto set the indicator 5l tothe estimated-ratew' of change of range in yards per unit of time say 3G seconds). Shaft l', when the clutch l-l' is in, rotates the shaft i3. This shaft, as before, rotates one arm of a differential another arm being set froni th e handtvheel il throu r te eof r M h' Handle il' W as before hasma follow#hzcliconnec'l tion through clutch 2e and shaft 3Q to the shaft S of the handwheel 5' to change the rate as Well as the indicated range. In this instance, however, no two speed arrangement is shown connection with the variable speed mechanism. It will be understood that the handwheel il' is rotated to set the follot/the-polnted dials lS and 35 to agree with the pointers 152 thereon, the latter being set every 30 seconds on the ring of the bell as before in accordance with the plotting board range readings. The original future range may be set in by the handwheel 36. Output shaft i8" and, therefore, shafts i8 and H3 geared thereto are rotated in accordance with the rate of change of range in yards per unit of time plus the original range setting.

The shaft HB is shown as rotating through a bevel gear drive 53-the shaft 55, on which is a cam 55 which We term the per cent range correction can. (see also Fig. 9). The position of this earn, therefore, is primarily a function of the total range' and the cam is preferably laid out so that its maximum lift is a predetermined percentage of the range, say 15% representing a maximum correction in range of that amount. Said cam lifts a pin 5S' thereon which bears at its outer end against a T-shaped lever 57 pivoted at 53. On said lever in turn bears a second lift pin '59 which is adjustable along the lever. vIt Will be evident, therefore, that the lift of pin 53 may be varied from zero when at the pivot 58 of the lever 5? to a maximum in either direction equal to the lift of the pin 55a as the pin 5a is shifted across said pivotal 'point 53 and toward either end. In between, its lift .is directly proportional to the distance from the pivot 58. The pin ,59 is shown as positioned along the lever to the proper per cent range correction positioned by a threaded shaft SG threaded through a triangular-sha-ped plate l and rotated from either or both of handwheels E2, d2. Said h-andwheeis are rotated to position the dials 63, 53 in accordance with the indicated spot and ballistic per cent corrections (respectively) in range as received, each correction being put in independently but added by differential l2! and transmitted through shafts 122 and 123.

The resulting lift of the pin 59 lifts a second triangular plate 93 pivoted .on shaft 58, which in turn lifts rod Ifl. Said rod in turn rotates shaft Sii through rack teeth i915 on the under surface of the pin meshing with the pinion 65 on said shaft. shaft et mms a second Shea which turns one arm of a differential gear the opposite arm S7 being turned from shaft i3, representing the plotting board uncorrected range,

(gto,

co1recton and, therefore,'represents corrected range. Arm 69 rotates one arm of the differential l gear'. Another arm of said gear train is turned ifrom the pinion '12 which is rotated from a lift rod S, While the third arm of said train turns rzero reading dialsv lil, '14. The duty of the opi erator of the crank 80 is to keep the dials lll, 'M' at zero thus providing in effect a manually operated follow-up system. Crank l5 is shown as secured to a shaft 131 which is both slidably andv rotatab-lymounted. To said shaft is secured a collar 120 so that when said crank is pushed inwardly it carries with it a disc 138 loosely mounted on said shaft and spring pressed against said collar by spring 139 which bears at its rear end against a second fixed collar 137. Said disc is normally prevented from rotating by pin 38',

A which engages a hole in xed bracket 138. Said v disc also carries a pin 135. In the position shown in Fig. 3 said pin engages a hole in the face of gear 135 to lock the same in a predetermined position.` There is also slidably but non-rotatably secured to shaft 131 the hub of pinion 132, which meshes with large gear 133, to the shaft of which is secured a pinion 13'11, the latter meshing` with the aforesaid gear 135. It will readily be seen,l

therefore, that shaft 131 cannot be rotated as long as pin 138 engages the hole in gear 135, but thatv by pushing in on the handle '15, pin 13B is released so that shaft 131 may be revolved through several revolutions until the pin 136 again drops into the hole.

Shaft 131 rotates through-shaft 'IG the shaft il of a single tooth pinion 'Il' (see also Fig. l0) which engages a rack bar 99 carrying the rod 73. The gear train 132 to 135 is so designed that 4only one revolution of the shaft '11 is permitted at a time, thus rotating single toothed pinion 'Il' through one revolution and likewise rotating the lift cam 199 through one revolution. The toothed pinion positions the. rod 'I3 on one or the other of a succession of range elevation cams 58. These cams are designed in accordance with the relations betvfeen range and elevation of the various type of guns, shells and powder charges employed, the proper cam being selected for particular conditions of firing at the moment. The range elevation cams IB are rotatedto the values of gun elevation' with' lifts equal to the range of that elevation. Said cams are rotated from handle 89,

through gearing 190 and 191, the amount of elevation being shown on the dials 181, 181.'. As each shift is made from one cam to another, the rod 'I3 is temporarily lifted by cam 10U on shaft T1 which lifts roller 101 on T-shaped piece 102 secured to rod 13. By the operation' of the handwheel 75 the range elevation cam pin '13 is shifted to the selected zone cam.

It is, of course, also true that the maximum range of a gun is reached at approximately c elevation so that all intermediate ranges may be obtained either by a greater or less elevation than 45 known generally as high and low angle firing. Also coupled with bar 98 as by bell crank levers 99 and 189 is a bar 182 which is thus shifted longitudinally on rotation of the shaft 7T. Said plate has a slot 183 therein through which appears one of the bands or rings 1811- on the low a plurality of concentric rings 184, 185, 18T and 188, etc., one for each of the zones. Each ring is adjustably mounted' upon said disc, the disc itself being `rotated from the handwheel 81.1' through gearing |99 and 191, 191'. portion of one of the rings is visible to the operator which is seen through the opening 183 in the shutter 182. One half of each ring may be white for low angle re, for instance, and the other half red for high angle fire. Each ring is made adjustable with respect to the disc so that the dividing line 189 between the two colors can be set in agreement with the point in its range elevation cam which represents maximum range, this varying from 45 with the particular type of gun, l5 etc. employed.

The operator of the handwheels '.'Sand SG must not only keep dials Td, lll reading zero but lie must also keep the proper color or zone indication visible on the indicator 185 to correspond to whether low or high angle fire is employed. In thus rotating the dials "M, l' the operator of handwheel 8G rotates the elevation cams sol that the cam selected by the operation of the handwheel lifts the pin 'I3 thus rotating the pinion 'i2 until the pointer 'ld again reads zero. The angle through which the cam T8 is rotated,'there fore, represents the elevation correction which is transmitted through the coarse and ne trans` mitters 99, 99 to the gun and which is also shown on dials i8! and 181. At 92 is shown a zone transmitter, the zone being shown also on dial 93.

In order that the plotting room operator may know what the future corrected range is to be at 3.3 a selected point P, an additional differential 9% is provided, one side of which is rotated from the' gear 9S as corrected range plus the spotters and ballistic correction (per cent range correction). Into the other side is fed the rate of change range 40 from the shaft 6 through gears 95, |15, 195 and 19'1. The output side of the differential is con nected to the dials 98, 98" which, therefore, shows the algebraic sum of Rp (corrected range) 40 7c :c Rp (percent range correction) dR (rate of change of' range per unit of time) If the point P is selected at seconds ahead, i. e., at an integral equal tol the unit of time employed (or at some known factor thereof), the dial 93 will show future or predicted corrected range factor from which the future range at the time the shell hits the target may be plotted on the board.

L1 using the range indicating portion of our. invention, the operator rst places the two clutches I4 and 20 in the off position and starts the variable speed drive 1', 4. The estimated rate of change of range is then set in the. instrument on the dial 51' by turning the handwheel 5. The uncorrected initial range is then. setA into the instrument on dials and 135" by turning the handwheel 36. The clutches irl' and 2B are then thrown in at the ring of the 30 second bell which starts the flow of uncorrected range data. The operator then sets the next reading of uncorrected range'on the instrument.' through the knobs 149 on dials 135, 135'. On the ring of the next 30 second bell,l the handle 1l' is quickly turned to match the pointers on the d ia s 135, 135 which corrects the value of range and at the same time applies a coirection to the rateg of change of range through the follow-back con- 575 Onl'y that 5 

